A sailboat sank in waters just off Keehi Lagoon, the Honolulu Fire Department said.

The Sea Dragon, which is about 30-feet long, capsized about 150 yards off the Ewa side of the piers at Keehi about 10:15 p.m. Tueday, said Honolulu fire Capt. Terry Seelig.

It was tied up to one of the mooring buoys when it apparently began to take on water. Three people, including the owner, tried to collect the items that had been in the boat, which appears to have been inhabited, Seelig said. No one was injured.

The boat appeared to have sunk rapidly and was completely underwater by the time fire and rescue personnel arrived, he said.

The boat’s owner told officials that the pump she had been using quit on her, and the vessel began taking on water, Seelig said.